Wooden cube puzzle solver

How to describe your puzzle

The site offers two modes. The first, “The most common 7-piece cube (Soma cube)”, is selected at the start: it shows the seven pieces of the Soma cube, with nothing to enter. Just tap “Find the solution”.

For any other set of pieces, choose “My pieces”. Each piece is drawn inside a 3 x 3 x 3 cube split into three layers: “Bottom layer”, “Middle layer” and “Top layer”. Every layer is a 3 x 3 grid, and each tap adds or removes a cube. A 3D drawing of the piece updates with every tap, so you can compare it with the real piece.

You start with three pieces and can have anywhere from 2 to 12, using the “+” and “−” buttons. Lay your pieces out in front of you, number them, then enter them one at a time. Each piece must be in one part, with its cubes touching face to face, and together the pieces must add up to exactly 27 cubes. If not, the site refuses to solve and says why: it names the piece that is empty or in several parts, or gives the total number of cubes your pieces make. Your entries are saved on your device.

How Emboîto finds the solution

Solving runs in your browser, on your phone or your computer, and your pieces aren't sent anywhere. It takes place in two stages.

First, Emboîto looks for a way of filling the 27 cells of the cube with your pieces. Each piece can be turned into any of its 24 orientations, but not flipped into a mirror image. The method, known as exact cover, rules out the placements that overlap or leave a gap.

Then it checks that the cube filled this way can really be assembled, piece by piece or in blocks. If it can't, it moves on to another way of filling the cube. It stops at the first one that works and builds the sequence of steps from it. Solving can take up to a minute, and the page stays usable in the meantime.

If your pieces don't form the cube, or if they form it but no assembly order works, the site tells you so. One piece has probably been entered wrongly. The assembly is then shown as written steps with a 3D animation, and you can print a PDF.

History and variants

The Soma cube was devised by Piet Hein in 1933. It consists of seven pieces: one made of three cubes and six made of four cubes, which makes 27 cubes in all. There are 240 distinct ways of forming the cube with these seven pieces.

Emboîto isn't limited to the Soma cube: it accepts 2 to 12 pieces of any shape, as long as they add up to 27 cubes and can form a 3 x 3 x 3 cube.

The site doesn't look for all 240 ways of building the Soma cube. It shows you a single solution, the first one it finds for your pieces, along with its assembly order. That is what you need to finish the cube you are holding.

Frequently asked questions

How many Soma cube solutions are there?

There are 240 distinct ways of forming the cube with the seven Soma pieces. Emboîto calculates only one of them, the first it finds, and shows you how to assemble it.

How do I find a wooden cube puzzle solution?

If you have the seven Soma pieces, keep the mode selected at the start and tap “Find the solution”. Otherwise, choose “My pieces”, set their number with “+” and “−”, draw each piece, then start solving.

What if my pieces don't form a cube?

If the total isn't 27 cubes, the site says so before any solving and gives the total it counted. If solving finds no possible cube, it says so too, afterwards. In both cases, one piece has probably been entered wrongly: compare each 3D drawing with the real piece, layer by layer.

Can I draw pieces that aren't the Soma pieces?

Yes, in “My pieces” mode: 2 to 12 pieces, each made of cubes touching face to face, adding up to 27 cubes.

Can I print the solution?

Yes. The “Download the solution (PDF)” button prepares an A4 document with every piece, then every step as a before and after picture.

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